has_many through & Collection Select issues

Question

I'm stumped. I'm getting an error of unknown attribute 'products_part' for Part. I'm starting with trying to create a new part that is associated with many different products through the products_parts table. Relevant code:

# schema.rb
create_table "products_parts", force: :cascade do |t|
  t.integer "product_id"
  t.integer "part_id"
  t.datetime "created_at", null: false
  t.datetime "updated_at", null: false
end

Just in case it's relevant, there is a product_id column existing on the parts table from my existing setup that only allowed one part per product. I don't think this would interfere though?

# part.rb
class Part < ApplicationRecord
  has_many :products_parts
  has_many :products, through: :products_parts

  accepts_nested_attributes_for :products_parts, :allow_destroy => true
end

# products_part.rb
class ProductsPart < ApplicationRecord
  belongs_to :product
  belongs_to :part
end

# product.rb
class Product < ApplicationRecord
  has_many :products_parts
  has_many :parts, through: :products_parts
  accepts_nested_attributes_for :parts, :allow_destroy => true
end

--

# parts_controller.html.erb
class PartsController < ApplicationController
  before_action :set_part, only: [:show, :edit, :update, :destroy]

  def new
    @part = Part.new
    @part.uploads.build
    @products_parts = @part.products_parts.build
    @product = Product.order(brand_name: :asc).order(manufacturer_model_number: :asc)
  end

  def create
    @part = Part.new(part_params)
      if @part.save
        redirect_to part_path(@part), notice: '// Part was successfully created.'
      else
        render :new
      end
  end


  private

    def part_params
      params.require(:part).permit!
    end

end

Parameters being passed on submit:

Request
Parameters:

{"utf8"=>"✓",
 "authenticity_token"=>"f+ObKsfs2QNP6l1MEDGSj6EZERMpHT/7vVKjAumC1aQmeTKdlPJNeSv2IZwNgsVPnKt2Siqi9x5oMmD2Ti8kMQ==",
 "part"=>
  {"products_part"=>{"product_ids"=>["", "191", "7"]},
   "manufacturer_model_number"=>"Screws-HB",
   "notes"=>""},
 "commit"=>"Create Part"}

-

# _form.html.erb
<%= bootstrap_form_for @part, url: parts_path, method: :post, :html => { :multipart => true } do |f| %>
  <%= f.fields_for(@products_parts) do |ff| %>
    <%= ff.collection_select(:product_ids, @product, :id, :product_select_with_model,
                             {:placeholder => "Select Product...", hide_label: true, :selected => @part.products.map(&:id)},
                             {:multiple => true, :class => 'newPartProductSearch', :style => "width:100%;"}) %>
  <% end %>
  <%= f.submit "Create Part", :style => "float:right;" %>
<% end %>

I am basing a lot of what I did here off of help from this post. If anybody has any ideas on what direction I can go to start fixing this, it would be appreciated!

Answer 1

Replace the _form with the following code:

# _form.html.erb
<%= bootstrap_form_for @part, url: parts_path, method: :post, :html => { :multipart => true } do |f| %>

  <%= f.collection_select(:product_ids, Product.all, :id, :name,
                          {include_blank: false, :include_hidden => false, :selected => @part.products.map(&:id)},
                          {:multiple => true}) %>

  <%= f.submit "Create Part", :style => "float:right;" %>
<% end %>

It is not tested. But hope it'll work.